Automatic mechanical test systems for checking functions of microelectronic arrangements, such as DRAM (Dynamic Random Access Memory) memory chips, are used in development and production. Normally, during measurements by an automatic mechanical test system, the memory chip to be measured is fixed on a printed circuit board. A test head with one or more test probes for recording electrical parameters, such as potentials, currents or resistances, is positioned on contact surfaces of the memory chip to be tested, on which contact surfaces a measurement is intended to be carried out. The test head is coupled to a mechanical apparatus which allows positioning on a plane and at right angles to the plane. A computation unit which is connected to the test head is used for evaluation of the measured signals, and for calculating and controlling positioning operations of the test head on the printed circuit board.
Before the use of an automatic measurement system, the test head is normally adjusted with respect to one or more reference points on the printed circuit board. Subsequent position determination processes can then be carried out with respect to coordinates of the reference points. On the basis of the prior art, the adjustment process was carried out by the user visually checking the automatic measurement system. Adjustment by eye is inaccurate and is dependent on the individual person for the necessary positioning accuracies, which may be in the order of magnitude of millimeters or even micrometers.
One known alternative to visual checking is the use of optical identification systems. However, additional fitting of an automatic measurement system for measurement of electrical parameters by means of an optical identification system is expensive and is technically complex.